i've always used a regular sized backpack and a small duffel bag but that was all i brought -for two adults. We always just put them under the seat. However, for this upcoming trip i bought fancy mickey luggage and now have an actual carry-on bag that rolls! so for the personal item (i have a question open about this, no answers though) I have been wondering what is allowed...i mean is it a size requirement or does it HAVE to technically be a purse, laptop, briefcase, or small backpack? I have a mickey duffel that is quite small and is 31 linear inches. For the personal item NorthWest says it cannot exceed 15x11x6. Mine is 15x7x9.
I called them since emailing was of no help. They said that if it can fit under the seat in front of you it is ok.
I think i'll bring it, I just wont pack it full. Another tough one on the backpack, since it says 'small.' I would measure it and see if it fits their size requirement.